1. Field of the Invention
The present invention relates generally to ink pumping systems for large-scale color printing presses, and more particular to a portable ink pumping system that is easily and quickly disassembled and cleaned so that changes in inks and varnishes can be readily accommodated. In particular, the present invention relates to a portable ink pumping system for supplying ink to a standard ink fountain of a printing press system.
2. Brief Description of the Prior Art
FIG. 1 is a schematic diagram illustrating a conventional large-scale color printing press system 100. In the conventional system 100, paper 102, wound on a large roll 104, is fed through a series of printing stations 106 before exiting at a finishing station 108, where the paper may be cut and/or folded. Each printing station 106 is set up to apply a designated color ink to the front and/or back side of the paper 102. Each printing station 106 includes an upper ink fountain 110, which contains ink to be applied to the top surface of the paper 102, and a lower ink fountain 112, which contains ink to be applied to the bottom surface of the paper. Ink to the upper and lower ink fountains 110 and 112 of the printing stations 106 is supplied via an arrangement of high pressure pipes 114a-d connected between the printing stations 106 and an ink supply station 116.
The ink supply station 116 typically includes four (4) separate drums or barrels 118a-d respectively containing red, blue, yellow and black ink, known in the trade as process inks. The colors red, blue, yellow, black and combinations thereof encompass the vast majority of color printing applications. The drums 118a-d typically contain 3,000-5,000 gallons of ink and are respectively connected to the ink feed pipes 114a-d through a dedicated heavy-duty piston-style pump 120a-d for supplying ink from the drums to the printing stations 106. The pumps 120a-d are permanently dedicated to pumping only one particular color ink supplied by their respective drums 118a-d. In other words, once a particular color ink is pumped through a pump and associated feed pipes, it is virtually impossible to change over to a different colored ink without having remnants of the prior ink contaminate the new ink. This is due in part to the difficulty of disassembling and thoroughly cleaning of traditional heavy-duty piston-style ink pumps and pipes.
Each printing station 106 includes a manifold 122 in fluid communication with each of the ink feed pipes 114a-114d. The manifold 122 includes quick-connect fittings that allows for selection of a particular colored ink to be fed to the ink fountains 110 and 112. Each ink fountain 110 and 112 includes an ink level control system (not shown), which continuously monitors the level of ink in the fountain and sends signals to its respective pump 120a-d to supply additional ink when needed. Unlike the ink supply station 116, the ink fountains 110 and 112 can be relatively easily cleaned to allow for filling of a different colored ink. This is important in that different printing jobs require different sequences in the application of ink colors.
However, because the ink level control system contains hard piping, it is not easily cleaned and each ink level control system is typically permanently dedicated to a particular ink. Thus, when changing inks in an ink fountain, it is necessary to also change the ink level control system.
While the process inks, i.e., red, blue, yellow and black, are typically sufficient for the majority of printing applications, it is often necessary or desired to apply a different ink at one or more of the printing stations. For example, with some specialty papers it is occasionally necessary to use a process ink having an alternative chemical formulation. Additionally, some printing applications require one or more non-process inks or specialty inks, as known in the trade. Such specialty inks include those colors that cannot be achieved by mixing the primary process colors, or those inks which include some type of distinctive feature that cannot be achieved by the primary process inks. Some examples of specialty inks include fluorescent inks, metallic inks, inks containing glitter, etc.
When it is desired to use something other than the standard process inks at one of the printing stations 106, it is necessary to clean the upper and/or lower ink fountain and to supply the fountain with the new ink. Depending on the volume of the printing application, such specialty inks are typically supplied in 3-55 gallon containers. Due in part to the extremely high viscosity of printing inks, even with the smallest 3 gallon container, an operator must manually scoop ink from the container and deposit the ink into the ink fountain. This procedure is obviously messy, wasteful and very labor intensive, particularly in larger volume applications requiring 50 or more gallons of ink.
Accordingly, it would be desirable to provide a portable system that can be moved between print stations for supplying non-standard or specialty inks to a desired ink fountain. Additionally, it would be desirable to provide such a system that can be easily disassembled and thoroughly cleaned and/or replaced to allow for rapid changing from one ink color to another, so that only one portable ink pumping system is required for one or more printing presses.
The present invention is a portable ink pumping system for supplying ink to a standard ink fountain of a printing station which generally includes a container, a progressive cavity pump, and an ink fountain mounting bar. Preferably the portable ink pumping system includes a cart made of a rigid frame construction for supporting the container and the progressive cavity pump in a vertical upright orientation, as well as the ink fountain mounting bar when not in use.
The container holds the ink and is an interchangeable component of the system. The container includes an opening through which a shaft of the pump is inserted for pumping ink from the container. A progressive cavity pump is utilized in the present invention due to the pump""s ability to be easily disassembled and thoroughly cleaned, allowing for quick change-over to a different ink.
The ink fountain mounting bar is designed to be releasably connected to a standard ink fountain of a printing station. The ink fountain mounting bar includes at least two ink dispensing nozzles which are preferably connected via flexible tubing to a mounting bar ink coupler. A suitable length flexible hose preferably connects the outlet of the pump to the mounting bar ink coupler of the ink fountain mounting bar to supply ink from the pump to the nozzles. The material of the nozzles, fittings, tubing and the hose allows for quick and thorough cleaning of any remaining ink within the conduits when an ink change is required. Moreover, when a radical ink color change is required, the nozzles, fittings, tubing and hose can be removed and replaced with new components. Thus, only one ink fountain mounting bar is required with the present invention, as opposed to multiple specific ink dedicated level control systems as typically required.
The ink fountain mounting bar also includes a proximity sensor for monitoring the level of ink within the standard ink fountain, and a control box for controlling the level of ink in the standard ink fountain. The control box also provides an operator interface to the pumping system. When the control box receives a signal from the proximity sensor associated with the ink level falling below a first predetermined value, the control box in turn sends a signal to the motor of the pump to activate the motor to supply additional ink to the ink nozzles of the mounting bar. The proximity sensor further deactivates the motor of the pump when the ink has reached a second predetermined value. The control box can be switched between automatic operation of the system, via the proximity sensor, and manual operation of the electric motor of the pump.
The advantage of the present invention is that after pumping one color ink, the pumping system can be easily disassembled and cleaned before changing over to a different ink. The working components of the pump, as well as the hose, the piping and the nozzles of the mounting bar, are easily separately cleaned with an ink cleaning solvent, or press wash, as known in the industry. Once all of the components are thoroughly cleaned or replaced, the system is reassembled, a new ink container is positioned on the cart and the system can be quickly moved to a new location.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.